Haplogroup A (Y-DNA)

Haplogroup A (Y-DNA) is It the foundational haplogroup. It includes the most recent common ancestor (MRCA) to all known patrilineal lineages carried by humans, Y-chromosomal Adam. It is mostly found in Africa. The most basal subclades of haplogroup A are "A00", "A0-T", "A0", "A1" and "A1a" and "A1b" and "A1b1". Haplogroup BT, the ancestral haplogroup to all non-African haplogroups, is a descendant of A1b.